Typically, granular products are discharged from storage and transportation containers as a result of gravity flow of the product towards an outlet positioned at the bottom of the container.
Granular products have been transported by road vehicle for perhaps 30 years. For most of this time the generally cylindrical shaped container formed part of the road vehicle. About five years ago containers have been introduced which are separate from the vehicle. The container, again of generally the cylindrical shape, is mounted in an ISO frame and the entire assembly is carried by the vehicle.
The bottom section of such known containers might be shaped to facilitate the discharge of the granular product. However, this has the disadvantages that the container, having a relatively complex shape, is expensive to manufacture and, since gas pressure is normally applied to the interior of the container to assist discharge of the product, the container, being of complex shape, will progressively suffer from fatigue.